Equalizing standing valve with hold-down



Aug. 1, 1961 D. E. DAFFlN 2,994,239

EQUALIZING STANDING VALVE WITH HOLD-DOWN Filed March 26, 1958 2 Sheets-Sheet 1 5. f. flaff/fl m INVENTOR.

A TI'bFP/VE y D. E. DAFFIN EQUALIZING STANDING VALVE WITH HOLD-DOWN Filed March 26, 1958 Aug. 1, 1961 2 Sheets-Sheet 2 D. f. flaff/fl INVENTOR.

This invention relates to a retrievable standing valve for oil or other fluid producing wells. More particularly, it deals with an improved check valve unit which on being passaged downwardly through a production conduit by a standard wire line running tool can be fitted to a landing nipple and securely anchored therein by a self acting latch whose latch effecting position is positively maintained against release under differential fluid pressures on the unit while upflow through the conduit is freely accommodated and downfiow is checked and which unit at any later time can be readily removed from operative position by engagement therewith of a conventional wire line pulling tool through which upward force is transmitted first to open a by-pass around the check valve for equalizing pressures above and below the same and then to break or release the latch connection for enabling the unit to be removed from the landing nipple and brought back to the surface.

Retrievable standing valves heretofore in common use have been rested on a landing surface and held under the head of liquid thereabove and have tended to unseat and rise above the landing surface under wide pressure differentials resulting when large fluid volumes are being produced through the restricted bore of the valve assembly. An unseated unit and one which fails properly to reseat itself causes unstable conditions with loss of previously raised fluid and a substantial reduction in operating efficiency of an artificial lift system, at considerable cost to the operator. To avoid such displacement and to positively maintain a valve unit in place until removal is intended is one of the objects of this invention.

A further object of the invention is to provide a valve body containing the usual reverse flow check valve and having a by-pass controlling sleeve valve slidably fitted between limit stops on the upper end of the body and formed with a suspending tool engaging head and with opposing upper and lower surfaces of substantially balanced areas and which balanced sleeve valve initially is releasably secured, as by a shearable connection, in a lowered or by-pass closing position and also having a retractable-projectable latch slidably fitted on a co-operatively shaped lower end of the body for slide travel to an upper limit accommodating latch retraction during downward passage through a landing nipple and for return slide travel to an intermediate position in which the latch is maintained projected in underlapping relation with the nipple and which intermediate position in the slide range is established by a stop abutment releasably secured, as by a shearable connection with the body. When located within a landing nipple, the body is held securely against differential fluid pressures above and below the valve body during normal functioning of the check valve. Should removal of the assembled unit be called for, a pulling tool is engaged with the sleeve valve to exert an upward pull thereon. Because of the balanced areas of the sleeve valve, such upward pull is free from restraint by the weight of liquid above the valve and because the previously projected latch securely anchors the valve body, the latch resistance to upward pull first causes breakage of the shearable connection between the sleeve valve and the body, thereby releasing the sleeve for travel to its upper limit, uncovering the by-pass around the standing valve unit for equalization of pressures on opposite sides F Ice 2,994,280

of the valve unit and minimization of resistance to final upward removal from the nipple. After the pressures have been equalized, further upward pull will be trans mitted from the sleeve valve to the main body and break the shearable connection between the body and the intermediate stop limit abutment bearing upwardly on the projected nipple underlapping latch, whereupon the latch is freed to drop to a bottom limit in which latch retraction to inoperative relation can take place for upward passage of the unit through the nipple and complete removal from the well.

Additional objects will become apparent from the following specification and the accompanying drawings in which FIG. 1 is a view partly in side elevation and partly in vertical section of the improved standing valve unit prior to being lowered into a well production conduit;

FIG. 2 is a view on a larger scale of a landing nipple.

constituting a part of the production string and being shown in vertical section with the lower portion of a valve assembly seated and latched within the nipple; FIG. 3 is a vertical section, with some parts in elevation, of the valve assembly in latch retaining position in the nipple but with the sleeve valve raised to its upper limit, in which the by-pass is open; and FIG. 4 is a combined part section and part elevation of the lower portion of the valve assembly partly raised from the landing nipple with the latch mechanism ineffective.

In the drawings the production string is shown as in? corporating at a predetermined point a landing nipple 1 which is of smaller internal diameter than the internal diameter of any part of the production string thereabove. Opposite ends of the nipple 1 provide a pair of vertically spaced apart seats comprising an upwardly facing abutment or landing seat 2 and a downwardly facing abutment or latch engaging seat 3. Both ends of the nipple preferably are chamfered at the internal corners to facilitate entry into the bore of the valve body to be fitted within the nipple.

The main body of the valve assembly is a hollow tube 4 having an intermediate portion of a diameter substantially corresponding to the internal diameter of the nipple 1 for close sealing fitment thereto below a downwardly facing stop shoulder or enlarged abutment 5 arranged to have seating engagement with the upwardly facing landing seat 2 of the nipple. The over-all length of the body 4 is greater than the length of the nipple 1 and when fitted to the nipple, an upper portion of the body extends above the nipple and a lower portion of the body extends below the nipple.

parts 6, 7, 8, and 9 which are terminally threaded one to another in end to end succession. The tubular parts 7 and 8 are for close fitting engagement within thenipple and they are peripherally formed to provide an annular pocket for the reception and retention of packing rings 10 to bear on the nipple interior face and seal against fluid leakage.

The bottom edge of the tubular part 8 affords an abut-. ment or upper limit stop 11 for a latch collar 12 which is slidably fitted on the lowermost tubular part 9. Throughout the major portion of its length the tubular body part 9 is of reduced peripheral diameter in relation to the tubular body part 8 and terminates downwardly in a peripherally enlarged head 16 providing an upper shoulder 14 to constitute a lower limit stop for the slide movement of the latch collar 12. The vertically spaced apart lat eral abutment seats 11 and 14, along with the reduced diameter intermediate portion of the body part 9, afford a spool-shaped retentive mounting for the slide collar 12.

The latter, which is preferably of spring steel stock, has. integrally formed therewith a series of circumferentially. spaced dependent spring blades or fingers 15, each of Patented Aug. 1, 1961.

For convenience of manufacture and assembly, the body 4 is made up of a series of tubular,

which terminates at its lower end in a laterally outwardly extending enlargement or latching lug 16.

The over-all length of the slidable latch inclusive of the collar '12 and its several dependent spring blades 15 is slightly less than the vertical distance between the lateral stop abutments 11 and 14 on the main body 4 and in the free or unstressed positions of the spring blades, as best seen in FIG. 1, the inner faces of the several blades are slightly laterally spaced from the peripheral surface of the reduced neck portion of the body part 9 a distance at least as great as the radial dimension of the latch projection 1'6 in excess of the thickness of the spring blade 15. The peripheral face of the latch collar 12 and the outer faces of the several spring blades 15, as seen in FIG. 2, are approximately in or just inside the cylindrical plane of the outer surface of the tubular body part 8 thereabovc. The innermost faces of the spring blades 15 and the peripheral face of the bottom head 13 of the lower body part will approximately correspond in diametrical dimension so that they may have a sliding fit one on another upon relative slide travel of the collar 12 away from and toward the top limit seat 11. In axial length the head 13 is much shorter than the length of the spring blades 15 whereby the lower terminals of the blades will extend considerably below the head whenever the slide collar is at its lowermost limit defined by the stop 14 as seen in FIG. 4.

I Prior to the threading of the upper end of the body part 9 into the lower end of the body part 3 and as a subassernbly operation, there will be fitted to the upper end of the body part 9 an annular ring 17 and one or more shear pins 18 will be inserted each through a tangentially extending opening through the ring 17 and through a peripheral notch in the wall of the body part 9. The location in length of the body part 9 of the shear pin receiving notch will be determined beforehand so as to locate the ring 17 at a position intermediate the range of collar slide travel between the stop limits 11 and 14 after final assembly of the parts has been completed. Such intermediate position, established by the releasable shear pin connection, restricts latch collar slide travel between the downwardly facing stop surface 11 and the upwardly facing upper edge surface of the ring 17 so that when the collar 12 is in bearing abutment with the intermediate limit ring 217 the lower ends of the several spring fingers 15 will overlap the enlarged terminal head 13 in the manner shown in FIG. 2 and the latter will positively buck or retain the spring blades against lateral retraction and in their outwardly projected position in which they extend radially for a distance in excess of the internal diameter of the nipple 1.

The uppermost body part 6 terminates at its upper end in a downwardly tapered ground seat for a ball check valve :19 which can be raised upwardly away from its seat within the limit afforded by a slotted cage 21 which terminates upwardly in a tool engaging spindle and head 21 and terminates downwardly in a cylindrical skirt extension 22 slidably sleeved on the tubular body portion 6. In the initial assembly of the parts the sleeve 22 is held releasably in a depressed position against sliding travel by means of -a shear pin or pins 23 extending partly through each the sleeve 22 and the upper end of the body part 6. Should the releasable or shearable pin connection at 23 be broken, the sleeve 22 can be moved upwardly to a limit established by a downwardly facing peripheral shoulder 24 on the part 6 in laterally overlapping relation to the upper face of a snap ring 25 fitted to an internal annular groove near the bottom of the sleeve 22. In that upper position a radial port or series of ports 26 through the sleeve will be radially aligned with an annular peripheral groove in the body part 6 and with which communicates one or more lateral ports 27 extending through the wall of the tubular body part 6 below its upper terminal ball valve seat. When such alignment is established, fluid above the ball check valve 19 can by-pass the same to the underside thereof and thereby equalize pressures.

So long as the sleeve valve 22 is held in its lower position by the releasable shear pin connection 23, the bypass ports will be out of the alignment with one another and the port 27 will be covered by the skirt wall of the valve 22. To prevent leakage along the inside surface of the sleeve valve, a pair of 0-rings 28 are carried in annular grooves in the tubular body part 6 above and below the lateral port 27 and in contact with the sleeve valve 22. The relative lengths: of the tubular body part 6 and the sleeve valve 22 will be such that prior to final assembly the body part 6 with the ball 19 in place can be inserted into the lower end of the sleeve and projected inwardly until the bottom of the sleeve 22 extends beyond the bottom of the body part 6 for enabling insertion of the snap ring 25 in its mounting groove. Then the parts will be adjusted until the openings for the shear pin 23 are in alignment and the shear pin will be inserted therethrough.

In the operation of installing the standing valve assembled in the relationship shown in FIG. 1, the upper coupling head 21 is engaged with a conventional running tool on a wire suspension line and the valve is lowered through the production tube to reach the landing nipple 1. The bottom terminal head 13 of the body and whose bottom corner is peripherally tapered downwardly, as seen in FIG. 1 will be received first within the nipple and as the lowering in operation continues the outwardly projecting lugs 16 of the slidable latch will come into contact with the nipple landing seat 2 and with the collar 12 in bearing engagement with its upper stop 11 the bottoms of the spring fingers will be depressed or cammed inwardly to ride down on the internal surface of the nipple 1 while received within the clearance space aiforded by the reduced diameter neck portion of the body part 9 above the head 13, such retraction being accommodated by inward bending deflection of the spring fingers 15 below the collar 12'. As downward travel proceeds, the stop shoulder 5 on the body will finally land on the upwardly facing seat 2 of the nipple and stop the descent. By that time the lower terminal lugs 16 on the spring fingers will have passed below and projected themselves under the downwardly facing abutment seat 3 of the nipple 1 and the collar 12 will be free to drop downwardly into engagement with the stop ring 17, at which time the bottoms of the spring fingers 15 will have overlapped the latch retaining head 13 and, as shown in FIG. 2, the lateral projections 16 will now be positively held in underlapping or latching relation with the bottom edge of the nipple 1. With the valve assembly thus properly seated and securely latched against accidental displacement, the running tool in the usual fashion can be uncoupled or jarred loose from the head 21 and removed from the well. Thereafter, flow of fluids through the nipple will be controlled by the check valve 19 in the usual fashion and there will be no likelihood of the assembly being blown upwardly from the nipple, no matter what the pressure differential.

For subsequent valve removal, a pulling tool will be lowered on a wire line and caused to grab or couple with the head 21. When a liquid column stands above the valve, as usually will be the case, the sustained liquid weight plus the latched in resistance, opposes upward force at the shear pin 23 imposed on the sleeve valve 22 by wire line tension. Thus, upward pull on the sleeve 22, with or without an additional jarring force, will release or shear the pin 23 and permit the sleeve to be raised until the abutments 24 and 25 come into engagement. It will be noted particularly that the sleeve valve component, including the necked spindle and coupling head 21, the slotted cage 20, and the lower tubular skirt 22, have upwardly facing areas and downwardly facing areas of equal sizes so that pressures on opposing surfaces are balanced. Accordingly, upward pull to lift the sleeve valve is not against the head of the liquid and the wire line equipment lifts no part of liquid column weight and is relieved of excessive stress, in the operation of uncovering the by-pass port for equalizing pressures above and below the check valve 19. After initial equalization has occurred, the valve assembly as a whole can be lifted without having to overcome the head of liquid, and continued upward pull is transmitted through the sleeve and the abutments 25 and 24 into the main valve body 4. An initial increment of upward travel brings the projected latch lugs 16 into abutment with the bottom face of the nipple 1 with the latch collar 12 hearing on the shear pin positioned stop ring 17. Either a constant upward pull or a jar or jerk force received by the body 4 and resisted by the nipple anchored latch, will then shear the pin 18 and release the connect-ion between the body and the intermediate stop ring 17. Relative additional upward travel of the now unlatched main body 4, while the latch projections 16 remain in contact with the nipple 1, will raise the enlarged bottom abutment head 13 on the body until the stop limit 14 engages with the ring 17 and picks up the latch collar 12. At such time the bottom head 13 will have passed to a distance considerably above the bottoms of the blades 15, substantially as shown in FIG. 4, and continued upward body movement lifts the latch unit and is accommodated by inward deflection of the spring blades below the head 13 as the enlarged lateral projections 16 are cammed back during passage through the internal bore of the nipple, permitting the tool to be raised clear and brought back to the surface.

If at the start of a pulling operation there should be absent an appreciable liquid column standing above the valve unit, opening of the by-pass ports may be unnecessary and may not occur. Under such condition, the anchorage latch is the main resistance to be overcome by upward wire line tug and the lower shear pin 18 may yield for an unlatching action under force transmitted through and Without cleavage of the upper shear pin 23.

In compliance with the statute, a single preferred embodiment of the invention has been described in detail, but it is to be understood the specific disclosure is not by way of limitation and modifications can be made as come within the scope of the appended claims.

What is claimed is:

l. A retrievable flow control unit to be mounted in a well conduit nipple and comprising a tubular body having a downwardly facing external landing shoulder, an upper body portion above said shoulder and a lower body portion below said shoulder, said lower body portion being spool-shaped and presenting a reduced diameter neck terminated in vertically spaced apart radial abutments, a collar slidable on said neck between said vertically spaced abutments and provided with a dependent spring finger terminated in a radial latch projection spaced from said collar a distance slightly less than the vertical space between said abutments and greater than the length of the lower abutment, said latch projection being movable with slide travel of the collar and between positions above and below said lower abutment and having radial alignment with the lower abutment when the collar is positioned on said neck at a point intermediate said upper and lower abutments, a stop element engageable by said collar at such intermediate position and releasably secured to said lower body portion, said upper body portion having a down flow resistant check valve therein and a passage through the wall thereof below said valve and a pulling tool engageable sleeve slidable on said upper body portion between an initially lowered position closing said passage and an upper position uncovering said passage for by-passing liquid around said valve.

2. In a flow control arrangement for a well production conduit containing a landing nipple which has vertically spaced apart upwardly and downwardly facing seats, a retrievable unit for reception in said nipple including a hollow body, nipple engageable sealing means carried peripherally by the body, a downwardly facing shoulder on the body for nipple seating engagement, at check valve housed by said hollow body and active against fluid downflow therethrough, said hollow body having a normally closed port through the wall thereof and which when uncovered permits fluid flow in by-pass relation with said valve, a port controlling sleeve slidably mounted on the body for travel from a lowered position in which it covers said port to a port uncovering upper position, a pulling tool engageable head fixed to said sleeve for the application of lift force thereon, co-operating seating faces on the sleeve and the body engageable with one another at the upper position of the sleeve for transmission of said lifting force to the body, means releasably securing the body and said sleeve in its lowered position, a laterally retractable latch, mounting means on the lower end of said hollow body slidably locating said latch, latch engageable stop abutments on the body establishing spaced apart limits of latch slide travel and accommodating latch retraction at either limit, an abutment formation on said hollow body arranged for retraction resisting engagement with said latch when the latter is positioned intermediate said vertically spaced apart limits and a positioning stop releasably secured to said hollow body and by its securement establishing an intermediate position of latch slide travel at which the latch engages and is held against retraction by said abutment formation.

3. In a flow control arrangement for a well production conduit containing a mounting nipple which has spaced apart upwardly and downwardly facing seats, a retrievable hollow body housing a check valve and having a downwardly facing shoulder to locate the body on the conduit nipple, a sleeve having a tool engageable formation and being slidable on said hollow body from a lower limit to an upper limit in response to lift force applied to said tool engageable formation, upper and lower spaced apart sleeve engageable abutments establishing said limits and the upper of which abutments upon sleeve engagement therewith serving to transmit lift force to the body from said tool engageable formation, means releasably holding said sleeve at its lower limit on said body, said body having a passage through the wall thereof arranged to be covered by said sleeve when the latter is held at its lower limit and to be uncovered by the sleeve at its upper limit and to accommodate fluid flow in by-passing relation with said valve, a latch slidably mounted on the lower end of said hollow body and retractable relative thereto at one limit of slide travel, an abutment releasably secured to said hollow body and thereby establishing another limit of latch slide travel and a formation on the hollow body positioned for radial alignment with said latch when the latter is at said last mentioned limit and engageable with the latch to maintain the same against retraction from beneath the downwardly facing seat of the nipple in which the body is fitted.

4. In a flow control arrangement for a well production conduit containing a landing nipple having upwardly and downwardly facing seats, a retrievable hollow body to be passaged through the conduit, a downwardly facing shoulder on the body for nipple landing engagement, a spoollike formation on the hollow body below said downwardly facing shoulder providing vertically spaced apart abutments separated by a reduced diameter neck which is of greater length than the lowermost of said abutments, a collar slidable on said reduced diameter neck and be tween the upper and lower limits afforded by said abutments, a retractable-projectable blade depending from said collar for a length greater than the length of the lowermost abutment to project therebelow for a distance that the blade lower end is clear of the lowermost abutment for blade end retraction at the time when said collar slides into engagement with said lowermost abutment and of a length less than the length of said neck to project wholly above said lowermost abutment for a distance that said blade lower end is clear of the lowermost abutment for blade end retraction when the collar slides into engagement with the uppermost of said abutments and a stop member engageable by said collar and releasably secured to said neck intermediate said abutments to position the lower end of said blade in retraction resisting radial alignment with said lowermost abutment at the time said collar engages said stop member, said blade having an outwardly projected latching formation adjacent said lower end.

5. In a flow control arrangement for a well production conduit containing a landing nipple, a retrievable hollow body, a downwardly facing shoulder on the body for positioning the same in said landing nipple, a collar sur rounding the lower end of said hollow body and having a dependent retractable-projectable spring blade terminating in a free end portion carrying a radially outwardly projected and upwardly facing latch, a reduced diameter neck portion on the hollow body on which said collar is slidably mounted for travel to and from an intermediate position and between opposite limits and said free end portion being spaced from the collar for a distance to be radially aligned with and held against retraction by the body below said reduced diameter neck portion at said intermediate position of the collar and to be aligned with the neck portion at one limit of collar slide travel and to be below the body at the other limit of slide collar travel and free to retract at either limit and a stop member releasably secured on said neck at an intermediate portion in the length thereof and engageable by said collar to locate the same at said intermediate position.

6. In a retrievable well tool, a main body, a terminal head at the lower end of said body having an outwardly facing abutment surface, a reduced neck portion above said head having longitudinally spaced apart top and bottom stop shoulders, a slide collar sleeved on said neck portion for travel within the limits of said stop shoulders, a longitudinally extending spring blade secured at its upper end to said slide collar and provided with an outwardly projected latch lug and with an inwardly facing surface at its lower end to seat against said outwardly facing abutment surface when the slide collar is at a predetermined intermediate position of travel between said top and bottom stop shoulders, said spring blade being of a length less than the space between said stop shoulders and presenting its lower end and said inwardly facing surface above said terminal head to accommodate retraction of the blade lower end within the reduced neck portion when the collar is at the upper travel limit afiorded by the top stop shoulder and a slide collar stop releasably secured on said body as a collar slide limit abutment at the intermediate position aforesaid and being releasable to permit downward slide collar travel to the bottom stop shoulder and the location of the lower end of the spring blade below and in retraction clearance relation to said terminal head.

7. In a retrievable well tool, a main body having a pair of longitudinally spaced apart abutment stops, a memher slidably mounted on the body for travel between said longitudinally spaced apart stops, a longitudinally extending latch blade having a fixed end carried by said member and having a free end projected from the fixed end for a distance less than the longitudinal space between said stops, said free end being retractable radially at opposite limits of member travel, a backing abutment on the body engageable by said free end of the blade when the slidable member is positioned at an intermediate point between said longitudinally spaced apart abutment stops and a stop element releasably connected to the body at said intermediate point and confining travel of said member between one of the abutment stops and said stop element prior to release of the stop element.

8. In a retrievable well tool, a main body having a latch positioning peripheral face of a given longitudinal dimension and an inwardly relieved portion extending longitudinally beyond said face for a distance greater than said given longitudinal dimension, longitudinally spaced apart stop abutments on the body defining the longitudinal limits of said relieved portion, a spring blade latch having one end portion slidably fitted to said relieved portion for longitudinal travel therein between said stop abutments and terminating in a free end portion spaced longitudinally from said one end portion a distance less than the spacing between said stop abutments and greater than said given longitudinal dimension of the peripheral face, said free end portion being inwardly retractable when located on either side of said latch positioning peripheral face at abutment limiting positions of said one end portion and being engageable with said latch positioning peripheral face in an intermediate part of the range of slide travel of said one end portion and a stop abutment releasably connected with the body in the path of and at an intermediate part of said range of slide travel.

References Cited in the file of this patent UNITED STATES PATENTS 61,447 Nicholson Ian. 22, 1867 172,227 Whipple Jan. 11, 1876 927,236 Hardison et al July 6, 1909 1,956,112 Willoughby Apr. 24, 1934 2,131,299 Reagin Sept. 27, 1938 2,392,244 Hooser Jan. 1, 1946 2,778,433 Brown Ian. 22, 1957 2,806,539 Green Sept. 17, 1957 2,816,613 Minter et al Dec. 17, 1957 2,839,144 Ault June 17, 1958 2,854,929 McGowen et a1. Oct. 7, 1958 2,871,947 Fredd Feb. 3, 1959 2,901,045 Schramm Aug. 25, 1959 2,944,605 Dollison July 12, 1960 FOREIGN PATENTS 331,604 Great Britain July 10, 1930 

